NVIDIA GPU resource change

[danielleodean]

AKS/Kubernetes moved Nvidia GPU resources from being an ‘alpha’ resource to a stable release, and changed the name of the resource on the cluster. Instead of requesting ‘alpha.kubernetes.io/nvidia-gpu’ now must request ‘nvidia.com/gpu’. I believe this issue affects anybody with a Kubernetes v1.10 or above cluster.

[msalvaris]

Addressed in #43 for PyTorch